Research on the Damage Behavior of the Aluminum Alloy Nozzle Closure in Solid Rocket Motor during the Bursting Process

When the aluminum alloy closure of the solid rocket motor nozzle is opened, tearing occurs at the root of the adhesive surface, which belongs to damage failure under a complex stress state. To help in the prediction and control of blasting pressure and nozzle closure failure morphology, this work designed and manufactured various shapes of 1060 aluminum alloy test specimens, performed damage tests, and calibrated the damage constitutive model parameters. The results gathered were utilized to create a finite element model of the nozzle aluminum alloy closure, and the blasting procedure was calculated. We conducted air pressure explosive tests on closures to confirm the finite element results. The numerical predictions and experimental results are very consistent, and the closure breaks along the adhesive surface. The constitutive characteristics obtained during material testing accurately characterize the closure’s damage process, providing a theoretical framework for the design and verification of aluminum alloy closures.